U.S. patent application number 13/732603 was filed with the patent office on 2014-01-30 for safety driving system of display device and safety driving method of display device.
The applicant listed for this patent is Young-Min BAE. Invention is credited to Young-Min BAE.
Application Number | 20140028650 13/732603 |
Document ID | / |
Family ID | 49994418 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140028650 |
Kind Code |
A1 |
BAE; Young-Min |
January 30, 2014 |
SAFETY DRIVING SYSTEM OF DISPLAY DEVICE AND SAFETY DRIVING METHOD
OF DISPLAY DEVICE
Abstract
A safety driving system of a display device includes a display
panel including at least one conductive detection line, the
conductive detection line extending in a predetermined area of the
display panel and being configured to detect voltage variation
according to damage in the predetermined area, a panel detector
configured to apply a reference voltage to one end of the detection
line, to receive an output voltage corresponding to the reference
voltage through the detection line from another end of the
detection line, to compare the received output voltage with a
predetermined normal voltage range, and to generate and output a
detection result signal, and a controller configured to provide a
detection set value for driving the panel detector and to interrupt
the driving of the display panel when the output detection result
signal indicates that the display panel is damaged.
Inventors: |
BAE; Young-Min;
(Yongin-City, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BAE; Young-Min |
Yongin-City |
|
KR |
|
|
Family ID: |
49994418 |
Appl. No.: |
13/732603 |
Filed: |
January 2, 2013 |
Current U.S.
Class: |
345/212 |
Current CPC
Class: |
G09G 2300/0426 20130101;
G06F 3/038 20130101; G09G 2330/045 20130101; G09G 2330/12 20130101;
G09G 3/20 20130101 |
Class at
Publication: |
345/212 |
International
Class: |
G06F 3/038 20060101
G06F003/038 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2012 |
KR |
10-2012-0081946 |
Claims
1. A safety driving system of a display device, comprising: a
display panel including at least one conductive detection line, the
conductive detection line extending in a predetermined area of the
display panel and being configured to detect voltage variation
according to damage in the predetermined area; a panel detector
configured to apply a reference voltage to one end of the detection
line, to receive an output voltage corresponding to the reference
voltage through the detection line from another end of the
detection line, to compare the received output voltage with a
predetermined normal voltage range, and to generate and output a
detection result signal; and a controller configured to provide a
detection set value for driving the panel detector and to interrupt
the driving of the display panel when the output detection result
signal indicates that the display panel is damaged.
2. The safety driving system of a display device of claim 1,
wherein the panel detector and the controller are included in a
driving IC, the driving IC being configured to operate the display
panel.
3. The safety driving system of a display device of claim 2,
wherein the driving IC further comprises a voltage input terminal
applying the reference voltage to the detection line and a voltage
output terminal receiving the output voltage from the detection
line.
4. The safety driving system of a display device of claim 1,
wherein the predetermined area is an edge area of the display panel
or an area adjacent to a driving IC driving the display panel.
5. The safety driving system of a display device of claim 1,
wherein the detection set value of the controller includes the
reference voltage, the predetermined normal voltage range, an
operation period, a driving interval of the panel detector, and an
analysis of the detection result signal.
6. The safety driving system of a display device of claim 1,
wherein the controller generates a control signal which stops or
soft-resets the operation of a driving IC operating of the display
panel or generates a control signal interrupting driving of a DC-DC
converter.
7. The safety driving system of a display device of claim 1,
further comprising a panel protector configured to receive an
operation starting signal according to the detection result signal
from the controller, and to generate a control signal which stops
or soft-resets the operation of the driving IC operating the
display panel or generates a control signal interrupting the
driving of a DC-DC converter.
8. The safety driving system of a display device of claim 1,
wherein the panel detector includes: an amplification circuit
configured to amplify the reference voltage before the reference
voltage is applied to the detection line; a complex comparator
including a first comparator comparing the output voltage output
from the detection line with a highest voltage value of the normal
voltage range and a second comparator comparing the output voltage
with a lowest voltage value of the normal voltage range; and a
combination logic configured to combine two logic signals output
from the first comparator and the second comparator of the complex
comparator to generate the detection result signal.
9. The safety driving system of a display device of claim 8,
wherein the amplification circuit includes an operational amplifier
and a push-pull circuit.
10. The safety driving system of a display device of claim 8,
wherein the panel detector further comprises at least one circuit
of at least one resistor configured to control a voltage value on a
circuit, at least one ESD circuit configured to protect the circuit
from static electricity generated outside, and a noise filter
configured to remove noise of a coupling factor influencing the
output voltage.
11. A safety driving method of a display device including a display
panel with at least one conductive detection line detecting voltage
variation according to damage to the panel in a predetermined area,
the method comprising: applying a reference voltage to one end of
the detection line; receiving an output voltage corresponding to
the reference voltage through the detection line from another end
of the detection line; comparing the received output voltage with
predetermined normal voltage range to generate a detection result
signal; and interrupting a driving of the display panel when the
detection result signal indicates damage to the display panel.
12. The safety driving method of a display device of claim 11,
further comprising, before applying the reference voltage to the
detection line, pre-setting detection set values, the detection set
values including the reference voltage, the normal voltage range,
an operation period, a driving interval of the panel detector, and
an analysis of the detection result signal.
13. The safety driving method of a display device of claim 11,
wherein interrupting the driving of the display panel includes
stopping operation of a driving IC driving the display panel,
soft-resetting the operation of the driving IC, or interrupting
driving of a DC-DC converter in the driving IC.
14. The safety driving method of a display device of claim 11,
wherein comparing the received output voltage with the
predetermined normal voltage range includes generating the
detection result signal by logic-combining a first result value
obtained by comparing the received output voltage with a highest
voltage value of the predetermined normal voltage range and a
second result value obtained by comparing the received output
voltage with a lowest voltage value of the predetermined normal
voltage range.
15. The safety driving method of a display device of claim 11,
wherein generating the detection result signal includes: removing
noise of a coupling factor influencing the received output voltage;
and removing static electricity generated outside.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. .sctn.119 priority
to and the benefit of Korean Patent Application No.
10-2012-0081946, filed in the Korean Intellectual Property Office
on Jul. 26, 2012, the entire contents of which are incorporated
herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Example embodiments relate to a safety driving system of a
display device and to a safety driving method of the display
device, and more particularly, to a driving apparatus capable of
improving safety by detecting an abnormal state due to damage to a
panel during driving of the display device and to a safety driving
system and a method using the same.
[0004] 2. Description of the Related Art
[0005] Recently, with development of a semiconductor manufacturing
technology and development of an image processing technology, flat
panel display elements, in which light weight and thinness of a
display device are easily implemented and high image quality
thereof can be implemented, have been rapidly commercialized and
expanded. For example, flat panel display devices include a liquid
crystal display (LCD), a field emission display (FED), a plasma
display panel (PDP), an organic light emitting diode (OLED)
display, and the like.
[0006] The LCD, the OLED, and the like among the display elements
of the flat panel display devices are widely applied to personal
portable apparatuses, e.g., a mobile phone, a PDA, a portable
computer, and the like due to their, e.g., light weight, thinness,
and high image quality. Particularly, the OLED, as a self-emission
element, receives attention as a next-generation display because
its thickness is reduced without requiring a backlight of the LCD,
its response speed is several tens of [ns] fast, its viewing angle
is wide, and a its contrast ratio is good.
[0007] However, since the display panel of the flat panel display
device is developed to have a large size, light weight, and small
thickness at the same time, durability against cracks, scratches,
or breakage due to an external impact may be required. For example,
when cracks or the like occur in the display panel, a short may be
generated in a power source applied to the display panel, so an
overcurrent flows in the panel and the temperature is increased. As
a result, the display panel may be burned. Further, due to the
generated short, a DC-DC converter may be under an overload
condition, the DC-DC converter or an inductor, i.e., a peripheral
component of the DC-DC converter, may brake, thereby influencing a
peripheral circuit.
SUMMARY
[0008] Example embodiments have been made in an effort to provide a
safety driving system of a display device capable of preventing a
screen from being abnormally displayed due to damage or capable of
preventing an error from being generated in a voltage supply, by
early detection of damage to a display panel to perform a driving
control of the display device according to a situation.
[0009] Therefore, it is possible to provide an apparatus and a
method for protecting the display device. The apparatus and display
according to example embodiments are capable of safely protecting
the display device from fire or overheating and are capable of
preventing a user of the display device from suffering a fatal
injury.
[0010] An exemplary embodiment provides a safety driving system of
a display device, including a display panel with at least one
conductive detection line, the conductive detection line extending
in a predetermined area of the display panel and being configured
to detect voltage variation according to damage in the
predetermined area, a panel detector configured to apply a
reference voltage to one end of the detection line, to receive an
output voltage corresponding to the reference voltage through the
detection line from another end of the detection line, to compare
the received output voltage with a predetermined normal voltage
range, and to generate and output a detection result signal, and a
controller configured to provide a detection set value for driving
the panel detector and to interrupt the driving of the display
panel when the output detection result signal indicates that the
display panel is damaged.
[0011] The panel detector and the controller may be included in a
driving IC operating the display panel.
[0012] The driving IC may further include a voltage input terminal
applying the reference voltage to the detection line and a voltage
output terminal receiving the output voltage from the detection
line.
[0013] The predetermined area may be an edge area of the display
panel or an adjacent area to the driving IC driving the display
panel.
[0014] The detection set value may include the reference voltage,
the normal voltage range, operation period and driving interval of
the panel detector, and an analysis of the detection result
signal.
[0015] The controller may generate a control signal which stops or
soft-resets the operation of the driving IC operating the display
panel or generate a control signal interrupting the driving of a
DC-DC converter.
[0016] The safety driving system of a display device may further
include a panel protector configured to receive an operation
starting signal according to the detection result signal from the
controller to generate a control signal which stops or soft-resets
the operation of the driving IC operating the display panel or
generates a control signal interrupting the driving of a DC-DC
converter.
[0017] The panel detector may include an amplification circuit
configured to amplify the reference voltage before the reference
voltage is applied to the detection line, a complex comparator
including a first comparator comparing the output voltage outputted
from the detection line with a highest voltage value of the normal
voltage range and a second comparator comparing the output voltage
with a lowest voltage value of the normal voltage range, and a
combination logic configured to combine two logic signals outputted
from the first comparator and the second comparator of the complex
comparator to generate the detection result signal.
[0018] The amplification circuit may include an operational
amplifier and a push-pull circuit.
[0019] The panel detector may further include at least one circuit
of at least one resistor configured to control a voltage value on a
circuit, at least one ESD circuit configured to protect the circuit
from static electricity generated outside, and a noise filter
configured to remove noise of a coupling factor influencing the
output voltage.
[0020] A safety driving method of a display device with a
conductive detection line detecting voltage variation according to
damage to the panel in a predetermined area may include applying a
reference voltage to one end of the detection line and receiving an
output voltage corresponding to the reference voltage through the
detection line from the other end of the detection line; comparing
the output voltage with a normal voltage range to generate a
detection result signal; and interrupting the driving of the
display panel when the damage to the display panel is determined by
the detection result signal.
[0021] The safety driving method may further include pre-setting
detection set values such as the reference voltage, the normal
voltage range, operation period and driving interval of the panel
detector, and an analysis of the detection result signal, before
applying the reference voltage to the detection line.
[0022] The interrupting of driving of the display panel may be any
one of stopping or soft-resetting the operation of the driving IC
operating the display panel or interrupting the driving of a DC-DC
converter.
[0023] Further, in the comparing of the output voltage with the
normal voltage range to generate the detection result signal, the
detection result signal may be generated by logic-combining a first
result value obtained by comparing the output voltage outputted
from the detection line with a highest voltage value of the normal
voltage range and a second result value obtained by comparing the
output voltage with a lowest voltage value of the normal voltage
range.
[0024] In the generating of the detection result signal by
comparing the output voltage with the normal voltage range, noise
of a coupling factor influencing the output voltage may be removed
and static electricity generated outside may be removed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a diagram schematically illustrating a display
device using a safety driving method according to an exemplary
embodiment.
[0026] FIG. 2 is a block diagram illustrating a configuration of a
safety driving apparatus of a safety driving system in the display
device according to an exemplary embodiment.
[0027] FIG. 3 is a circuit block diagram illustrating a panel
detector of the safety driving apparatus of FIG. 2.
[0028] FIG. 4 is a signal waveform diagram describing a safety
driving method in a display device according to an exemplary
embodiment.
DETAILED DESCRIPTION
[0029] Example embodiments will be described more fully hereinafter
with reference to the accompanying drawings. As those skilled in
the art would realize, the described embodiments may be modified in
various different ways, all without departing from the spirit or
scope of the inventive concept.
[0030] Further, in exemplary embodiments, since like reference
numerals designate like elements having the same configuration, a
first exemplary embodiment is representatively described, and in
other exemplary embodiments, only a configuration different from
the first exemplary embodiment will be described.
[0031] The drawings and description are to be regarded as
illustrative in nature and not restrictive. Like reference numerals
designate like elements throughout.
[0032] Throughout this specification and the claims that follow,
when it is described that an element is "coupled" to another
element, the element may be "directly coupled" to the other element
or "electrically coupled" to the other element through a third
element. In addition, unless explicitly described to the contrary,
the word "comprise" and variations such as "comprises" or
"comprising", will be understood to imply the inclusion of stated
elements but not the exclusion of any other elements.
[0033] FIG. 1 is a diagram schematically illustrating a display
device using a safety driving method according to an exemplary
embodiment.
[0034] In detail, the display device of FIG. 1 controls driving of
the display device by using a detection line capable of detecting
defects, e.g., cracks, scratches, or breakage, on a display panel
and determining the damage to the display panel from the detected
defects. As a result, as illustrated in FIG. 1, the display device
applying a driving method in accordance with example embodiments
includes a display panel 1 with the detection line.
[0035] In general, the display device is may include a display
panel which receives an external image signal to display an image
according to the external image signal and a driving IC configured
of a plurality of driving circuits which supply a driving signal, a
data signal, and the like to operate the display panel so that the
image is displayed on the display panel.
[0036] In FIG. 1, the detection line capable of detecting damage,
e.g., cracks and scratches, due to an external impact is provided
on the display panel 1, and a layout form thereof may Vary. For
example, as illustrated in FIG. 1, the detection line may have a
form like a detection line 3-1 installed along a four-sided edge of
the display panel 1. In another example, as further illustrated in
FIG. 1, the detection line may have a form like a detection line
3-2 surrounding and adjacent to a driving IC 2.
[0037] In detail, the detection line 3-1 is disposed in an area
including an edge of the display panel 1. For example, the
detection line 3-1 may extend along a perimeter of the display
panel 1 to be only in a periphery of the display panel 1, e.g., to
trace lengths of at least three sides of the display panel 1.
[0038] The detection line 3-2 is disposed only in an area of a
chip-on glass (COG) circuit of the driving IC 2. For example, the
detection line 3-2 may extend along the driving IC 2.
[0039] The detection lines 3-1 and 3-2 may be made of any suitable
materials. For example, the detection lines 3-1 and 3-2 may be made
of conductive metal lines capable of being influenced by a current
flow against damage, e.g., cracks, of the display panel.
[0040] The detection lines 3-1 and 3-2 are connected with the
driving IC 2. In detail, the detection lines 3-1 and 3-2 may be
connected with a safety driving apparatus (to be described below in
a subsequent drawing), which is included in the driving IC 2 to
determine the damage on the panel and to control the driving of the
display device according to the determination. According to another
exemplary embodiment, even if the safety driving apparatus is be
disposed in the driving IC 2, both ends of the detection lines 3-1
and 3-2 are connected with the safety driving apparatus, i.e., so
the safety driving apparatus detects whether or not cracks occurs,
thereby controlling the driving.
[0041] Referring to FIG. 1, both ends of the detection line are
connected to the safety driving apparatus (not shown) included in
the driving IC 2, of which one end is a voltage input terminal 21
to which a reference voltage is applied and the other end is a
voltage output terminal 22 outputting voltage of the reference
voltage by returning a path of the detection line. A safety driving
system of the example embodiments applies a predetermined reference
voltage to the voltage input terminal 21 of the detection line,
detects the output voltage thereof through the voltage output
terminal 22, and monitors whether a part of the display panel 1 is
damaged.
[0042] That is, if a part of the display panel 1 is damaged, e.g.,
due to cracks, scratches, or the like, the detection line is
electrically influenced by the damage, and the output voltage at
the voltage output terminal 22 deviates from a normal output range.
For example, when a short occurs due to damage, an excessive
current flow through the detection line, so the detected output
voltage may exceed an upper limit of the normal output range. In
another example, when an open occurs due to damage, the current
amount flowing in the detection line is decreased, so the detected
output voltage may be smaller than a lower limit of the normal
output range.
[0043] In other words, when damage, e.g., cracks or scratches,
occurs in the display panel 1, the detection line, i.e., the
detection line 3-1 and/or the detection line 3-2, enables detection
of such damage by monitoring only the signal therethrough. In other
words, the detected result of the detection lines only influences a
signal itself. In contrast, when similar damage occurs in a
conventional panel display, i.e., a display panel without a
detection line, the damage may be detected only when a power
generated in the driving IC is influenced.
[0044] The safety driving system of the example embodiments detects
the output voltage flowing out of the detection line to determine
whether or not the display panel is damaged. The determination is
done by determining whether a detection result signal, i.e., the
detected output voltage, is within a predetermined output voltage
range relative to a given reference voltage.
[0045] FIG. 2 is a block diagram illustrating a configuration of a
safety driving apparatus of a safety driving system in a display
device according to an exemplary embodiment.
[0046] As described above, the safety driving apparatus may be
installed in the driving IC 2, but is not limited thereto and may
be installed outside. In the case where the safety driving
apparatus is installed outside, the safety driving apparatus is
connected with the driving IC 2 in order to transmit and receive a
signal for controlling an operation of the driving IC 2. For
example, a safety driving apparatus 4 of FIG. 2 is included in the
driving IC 2 in FIG. 1.
[0047] The safety driving apparatus 4 detects the output voltage
according to the applied reference voltage from the detection line
installed on the display panel 1. Further, the safety driving
apparatus 4 detects damage, e.g., cracks in the display panel 1,
according to variation of the detected output voltage. Thus, when
the damage to the display panel 1 is detected, the safety driving
apparatus 4 interrupts an operation of an internal driver included
in the driving IC 2 of the display device, thereby protecting the
display panel 1. Here, the internal driver drives operations of
various devices for implementing an image of the display device,
e.g., may include a power source driver supplying power. In this
case, the power source driver may be a DC-DC converter, e.g., the
DC-DC converter may boost and output a constant voltage supplied
from an external power source to a driving voltage of the display
panel 1.
[0048] The safety driving apparatus 4 of FIG. 2 includes a panel
detector 41, a controller 43, and a panel protector 45.
[0049] The panel detector 41 detects damage, e.g., cracks of the
display panel. The panel detector 41 is connected to the voltage
input terminal 21 and the voltage output terminal 22 of FIG. 1,
respectively. The panel detector 41 applies a reference voltage
Vref to the voltage input terminal 21 to form a current path around
the detection line installed on the display panel 1. The panel
detector 41 detects an output voltage Vo from the voltage output
terminal 22, i.e., a last terminal of the detection line, to
generate a detection result signal by comparing a highest voltage
value and a lowest voltage value in the normal range for the
reference voltage, respectively. A detailed circuit configuration
of the panel detector 41 will be described below with reference to
FIG. 3.
[0050] The controller 43 supplies various set values for detecting
whether or not the display panel 1 is damaged in accordance with
the detection result signal of the panel detector 41. That is, the
controller 43 determines whether the detection result signal
generated by the panel detector 41 is a signal in the normal
voltage range of the reference voltage or a signal outside the
normal voltage range in order to verify whether or not the display
panel 1 is damaged.
[0051] The values set in the controller 43 are not particularly
limited, but may include detection set values such as the reference
voltage applied to the display panel, the normal voltage range of
the output voltage for determining whether or not the display panel
1 is normal, a detection period and a detection interval of the
output voltage, and an analysis of the detection result signal.
[0052] The normal voltage range of the output voltage depends on
the reference voltage. As the reference voltage value is increased,
a difference between the highest voltage value and the lowest
voltage value of the normal voltage range may be increased.
[0053] The detection period and the detection interval of the
output voltage may be set as a length of an operation period of the
safety driving apparatus, e.g., operation of the panel detector,
and a period corresponding to the operation interval,
respectively.
[0054] The analysis of the detection result signal is to set an
option of a logic analysis for determining whether the panel is
normal or damaged by using the detection result signal. For
example, according to a circuit configuration and a logic
combination of the panel detector, when the detection result signal
is at a high level, a normal display panel, i.e., without damage to
the display panel 1, may be represented. In another example, when
the detection result signal is at a low level, a damage display
panel 1 may be represented.
[0055] Further, in order to monitor the operations of the panel
detector 41 and the panel protector 45, polarities of signals
transferred to a monitoring terminal may be set. Meanwhile, the
controller 43 may generate and transfer respective starting signal
initiating operations of the panel detector 41 and the panel
protector 45.
[0056] The panel protector 45 generates and transfers a control
signal which interrupts or performs operations of various drivers
of the display device, e.g., a plurality of drivers included in the
driving IC 2 and a power source driver controlling a driving
voltage applied from an external power source. That is, when the
controller 43 receives the detection result signal from the panel
detector 41 representing damage to the display panel 1, the
controller 43 transfers the operation starting signal to the panel
protector 45 so as to prevent a fire due to an overcurrent flowing
in the display panel 1 by interrupting the driving of the display
device. In other words, when the controller 43 receives a signal
from the panel detector 41 indicating that the display panel 1 is
damaged, the controller 43 transmits a signal to the panel
protector 45 to indicate that operation of the display device
should be stopped.
[0057] Then, the panel protector 45 generates and transfers a
control signal which stops or soft-resets the operation of the
driving IC 2 or a control signal interrupting the driving of the
power source driver, e.g., the DC-DC converter. As a result,
operation of the driver is stopped, thereby stopping operation of
the display panel. Accordingly, overcurrent does not flow, thereby
preventing overheating of the display device.
[0058] In the exemplary embodiment of FIG. 2, the controller 43 and
the panel protector 45 are separately configured, but are not
necessarily limited thereto. That is, the controller 43 generates a
control signal which directly stops or soft-resets the operation of
the driving IC 2 or a control signal interrupting the driving of
the power source driver, e.g., the DC-DC converter, to interrupt
the driving the display panel, when the detection result signal
represents the damage to the display panel.
[0059] FIG. 3 is a block diagram illustrating a circuit
configuration diagram of the panel detector 41 of the safety
driving apparatus 4 of FIG. 2. The circuit elements configuring the
panel detector of FIG. 3 are not limited to the exemplary
embodiment and may include various circuit elements properly
controlling voltage values on the circuit in order to determine
whether a voltage output through a path of the detection line is
included in a predetermined normal voltage range.
[0060] Referring to FIG. 3, the panel detector 41 includes an
operational amplifier 10, a push-pull circuit 11, a plurality of
resistors R1 through R6, a plurality of ESD circuits 12, a noise
filter 14, a complex comparator 15, and a combination logic 16.
[0061] The operational amplifier 10 and the push-pull circuit 11
are connected to a front end of a load 13, and the complex
comparator 15 and the combination logic 16 are connected to a rear
end of the load 13. In some cases, the push-pull circuit 11, the
plurality of resistors R1 through R6, the plurality of ESD circuits
12, and the noise filter 14 may be omitted, and the number and the
size of the plurality of resistors may be controlled in response to
the range of the output voltage. Here, the load 13 refers to a
conductive detection line installed on the display panel.
[0062] The reference voltage Vref set in the controller 43 is
applied to the detection line, i.e., to the load 13, through the
predetermined circuit elements, e.g., through the operational
amplifier 10, the push-pull circuit 11, and the resistor.
[0063] In the circuit diagram of FIG. 3, the operational amplifier
10 is configured of an inversion amplifier, but is not limited
thereto and may be configured of a non-inversion amplifier
according to a set value of the reference voltage Vref. The
operational amplifier 10 of FIG. 3 inverts and outputs a voltage
waveform polarity before the reference voltage Vref is applied to
the detection line through the voltage input terminal. The
reference voltage Vref is applied to an inversion terminal (-) of
the operational amplifier 10 as an input voltage, and a ground
voltage GND is applied to a non-inversion terminal (+). In
addition, the polarity of the reference voltage Vref is reversed to
be outputted to the output terminal of the operational amplifier
10. In this case, the output voltage is referred to as a first
output voltage Vo1.
[0064] Although not shown in the circuit diagram of FIG. 3, an
input resistor is installed at the front end of the inversion
terminal (-) or a resistor is additionally connected to the front
end of the inversion terminal (-) as a feedback circuit connecting
the inversion terminal (-) and the output terminal of the
operational amplifier 10, thereby amplifying or controlling the
first output voltage Vo1.
[0065] The first output voltage Vo1 output from the output terminal
of the operational amplifier 10 may be input to the push-pull
circuit 11. The push-pull circuit 11 has a structure in which two
transistors, that is, a PMOS transistor and an NMOS transistor
which complementarily operate are connected between a supply source
of a first power source voltage VDD and a ground terminal. In FIG.
3, a source electrode of the PMOS transistor is connected to the
supply source of the first power source voltage VDD, and a source
electrode of the NMOS transistor is connected to the ground
terminal. In addition, respective drain electrodes of the PMOS
transistor and the NMOS transistor are commonly connected to the
output terminal. In this case, a second output voltage Vo2
corresponding to the first output voltage Vo1 is outputted to the
output terminal. Further, gate electrodes of the PMOS transistor
and the NMOS transistor are commonly connected to the input
terminal to receive the first output voltage Vo1 outputted from the
output terminal of the operational amplifier 10.
[0066] When the first output voltage Vo1 output from the
operational amplifier 10 is input, the PMOS transistor is turned on
in the voltage range between the first power source voltage VDD and
the ground voltage GND in response to the voltage value to take
charge of amplification of a positive (+) voltage value, or the
NMOS transistor is turned on to take charge of amplification of a
negative (-) voltage value. Accordingly, in the case of the
positive (+) voltage value, the voltage range of the second output
voltage Vo2 is a highest voltage value of the first power source
voltage VDD, and in the case of the negative (-) voltage value, the
voltage range is a lowest voltage value of the ground voltage
GND.
[0067] For example, in the case where the reference voltage Vref is
set to (+2) V, the first output voltage Vo1 passing through the
operational amplifier 10 has a negative (-) voltage value, and the
first output voltage Vo1 turns on the PMOS transistor above the
push-pull circuit 11 to output a high level voltage as the second
output voltage Vo1. In this case, the high level voltage does not
exceed the first power source voltage VDD. In addition, the NMOS
transistor is turned off. When the reference voltage Vref is
differently set, the operation of the push-pull circuit 11 and the
voltage value of the second output voltage Vo2 are varied.
[0068] The second output voltage Vo2 is applied to the load 13 in a
state where the voltage value is controlled by at least one
resistor R1 having a predetermined magnitude. In this case, the ESD
circuit 12 protecting a circuit from static electricity may be
installed at the front end of the load 13. The ESD circuit 12 may
remove the static electricity which is generated abound the panel
detector and influences determination of the damage to the panel or
not.
[0069] Since the ESD circuit 12 is basically unrelated to the
content of the example embodiments as a known static electricity
protection circuit, the description for a detailed circuit
structure will be omitted. However, the panel detector 41 of FIG. 3
includes a ESD circuit 12 configured of at least one resistor R2
between the supply source of the first power source voltage VDD and
the voltage input terminal of the load 13, and a ESD circuit 12
configured of at least one resistor R3 between the ground terminal
and the voltage input terminal of the load 13.
[0070] The second output voltage Vo2 passes through the resistor,
the ESD circuit, and the like to be inputted to the voltage input
terminal of the load 13 as a third output voltage Vo3.
[0071] An output voltage value which turns a detection line path as
the load 13 to be outputted to the voltage output terminal of the
load 13 is referred to as a fourth output voltage Vo4.
[0072] According to an exemplary embodiment, as shown in FIG. 3,
the voltage output terminal of the load 13 may include an ESD
circuit 12 protecting a circuit of the panel detector from the
static electricity. That is, the voltage output terminal of the
load 13 includes a ESD circuit 12 configured of at least one
resistor R4 between the voltage output terminal of the load 13 and
the supply source of the first power source voltage VDD, and a ESD
circuit 12 configured of at least one resistor R5 between the
voltage output terminal of the load 13 and the ground terminal.
[0073] The voltage value of the fourth output voltage Vo4 is
controlled while passing through the ESD circuit and at least one
resistor R6.
[0074] In addition, according to an exemplary embodiment, the
fourth output voltage Vo4 may pass through the noise filter 14.
[0075] Since a coupling factor capable of influencing voltage
levels of the voltage input terminal and the voltage output
terminal of the load 13 may variously exist, the panel detector 41
of FIG. 3 includes the noise filter 14 to remove a coupling noise
so as to exactly detect only the influence of the output voltage
value due to the damage according to an impact of the display
panel. In FIG. 3, the noise filter 14 is included in the rear end
of the voltage output terminal of the load 13, but is not
necessarily limited thereto.
[0076] In addition, the noise filter 14 may be designed according a
size of the panel and a load amount so as to properly filter the
coupling noise capable of occurring in a layout of the display
panel. The fourth output voltage Vo4 passes through the noise
filter 14 to be output to a fifth output voltage Vo5. The fifth
output voltage Vo5 is applied to the complex comparator 15.
[0077] In detail, the fifth output voltage Vo5 is transferred to
two comparators 15-1 and 15-2 included in the complex comparator
15, respectively to be compared with the highest voltage value and
lowest voltage value of the normal voltage range set in response to
the reference voltage Vref, respectively. That is, the controller
43 sets a deviation range for the reference voltage of the output
voltage which can be determined as the normal display panel,
together with the setting of the reference voltage Vref. When the
normal voltage range is set, a highest voltage value Vr_high which
is a higher voltage than the reference voltage Vref by a
predetermined deviation and a lowest voltage value Vr_low which is
a lower voltage than the reference voltage by the deviation are
pre-set.
[0078] For example, in the case where the reference voltage Vref is
(+2) V, a deviation having the predetermined normal voltage range
may be set as 0.75 V, and in this case, the highest voltage value
Vr_high may be set as (+2.75) V and the lowest voltage value Vr_low
may be set as (+1.25) V.
[0079] The controller 43 may largely set a deviation which is the
reference of the normal voltage range so as to highly set the
voltage level of the reference voltage Vref.
[0080] The complex comparator 15 of the panel detector 41 compares
the fifth output voltage Vo5 output through the load 13 with the
highest voltage value Vr_high and the lowest voltage value Vr_low,
respectively. Then, the complex comparator 15 outputs result values
obtained by comparing the fifth output voltage Vo5 with the highest
voltage value Vr_high, and the fifth output voltage Vo5 with the
lowest voltage value Vr_low as a high or low logic signal,
respectively.
[0081] In addition, the combination logic 16 is installed in the
output terminal of the complex comparator 15 to properly
logic-combine the outputted logic signals according to each
comparator and divide a result signal in the case of the voltage
range of the normal panel and a result signal in the case of the
voltage of the damaged panel to be outputted as a detection output
signal PCD_out.
[0082] If the fifth output voltage Vo5 is in the range of the
highest voltage value Vr_high and the lowest voltage value Vr_low,
the detection output signal PCD_out through the complex comparator
15 and the combination logic 16 may be output as the result signal
which indicates a normal display panel. If the fifth output voltage
Vo5 is higher than the highest voltage value Vr_high or lower than
the lowest voltage value Vr_low, the detection output signal
PCD_out may be output as the result signal which indicates a
damaged display panel.
[0083] Since a configuration and a logic combination method of the
combination logic 16 may vary according to a configuration of the
complex comparator 15 and levels of the input-output signals of the
entire circuit of the panel detector 41, detailed description
thereof will be omitted.
[0084] Meanwhile, referring to FIG. 3, the complex comparator 15
may be configured of two inversion comparators, but is not
necessarily limited thereto. In detail, the complex comparator 15
of FIG. 3 is configured of a first comparator 15-1 comparing the
fifth output voltage Vo5 with the highest voltage value Vr_high and
a second comparator 15-2 comparing the fifth output voltage Vo5 and
the lowest voltage value Vr_low.
[0085] The first comparator 15-1 receives the fifth output voltage
Vo5 to the inversion terminal (-), receives the highest voltage
value Vr_high to the non-inversion terminal (+), and compares both
voltage values to output a corresponding logic signal (high-level
signal or low-level signal) to the output terminal in response to
the high level voltage. In this case, a form of the output logic
signal depends on the reference voltage Vref and the voltage set
value of the normal voltage range.
[0086] A case where the reference voltage Vref is (+2) V, the
highest voltage value is (+2.75) V, and the lowest voltage value is
(+1.25) V will be described as an example. In the case where the
fifth output voltage Vo5 is lower than the highest voltage value of
(+2.75) V, the high-level logic signal is output in response to the
highest voltage value of (+2.75) V, and in the case where the fifth
output voltage Vo5 is higher than the highest voltage value of
(+2.75) V, the fifth output voltage Vo5 is phase-inverted and thus
the low-level logic signal corresponding thereto may be output.
[0087] Further, the second comparator 15-2 receives the fifth
output voltage Vo5 to the inversion terminal (-), receives the
lowest voltage value Vr_low to the non-inversion terminal (+), and
compares both voltage values to output a corresponding logic signal
(high-level signal or low-level signal) to the output terminal in
response to the high-level voltage. In the example, in the case
where the fifth output voltage Vo5 is lower than the lowest voltage
value of (+1.25) V, the high-level logic signal is output in
response to the lowest voltage value of (+1.25) V, and in the case
where the fifth output voltage Vo5 is higher than the lowest
voltage value of (+1.25) V, the fifth output voltage Vo5 is
phase-inverted and thus the low-level logic signal corresponding
thereto may be output.
[0088] Then, the logic signal of each comparator outputted from the
output terminal of the complex comparator 15 is transferred to the
combination logic 16 and divided into the logic signals of the case
of the normal display panel and the case of the damage display
panel to be output as the detection result signal PCD_out.
[0089] In the example, when a part of the display panel is shorted
due to an external impact, and when the fifth output voltage Vo5
exceeds the highest voltage value of (+2.75) V, the first
comparator 15-1 of the complex comparator 15 may output the low
signal and the second comparator 15-2 may output the low signal.
Further, in the case where the part of the display panel is opened
due to the external impact, and when the fifth output voltage Vo5
may be lower than the lowest voltage value of (+1.25) V, the first
comparator 15-1 of the complex comparator 15 may output the high
signal and the second comparator 15-2 may output the high
signal.
[0090] Then, the combination logic 16 combines the logic signal
output from the abnormal display panel to generate the detection
result signal PCD_out as a high signal or a low signal. That is,
the combination logic 16 is configured of various logic gates to
output the detection result signal PCD_out by combining the logic
signals transferred from the complex comparator 15.
[0091] At this time, in the case of the normal display panel, since
the first comparator 15-1 of the complex comparator 15 output the
high signal and the second comparator 15-2 output the low signal,
the combination logic 16 receives logic signals having different
phases to output a logic signal which is different from the
detection result signal PCD_out of the abnormal display panel. That
is, the logic gates configuring the combination logic 16 are
combined so that phases of the detection result signals PCD_out of
the normal panel and the abnormal panel are different from each
other.
[0092] FIG. 4 is a signal waveform diagram describing a safety
driving method in the display device according to the exemplary
embodiment.
[0093] First, at a time t1, a level of a battery voltage VBAT for
driving the display device is increased. Then, for a predetermined
period of the time t1 to a time t2, a driving IC of the display
device is boosted.
[0094] Then, at the time t2, an enable signal EL_ON for driving a
power source driver controlling supply of an external voltage,
particularly, an external DC-DC converter, is increased to an
on-level. The display device operates in response to the enable
signal EL_ON and organic light emitting elements of the display
panel are driven, thereby displaying images.
[0095] The safety driving system of the display device according to
the exemplary embodiment may be set so as to operate with a delay
period corresponding to a period of the time t2 to a time t3. That
is, the controller 43 of the safety driving apparatus in the
driving IC may set the safety driving system to operate
simultaneously with the driving of the display device, or set the
safety driving system to operate after the delay period elapses.
Further, the controller may set a period (duration) when the safety
driving apparatus operates.
[0096] At the time t3, the safety driving system of the display
device operates in response to an operation starting signal PCD_ON
of the safety driving apparatus which is generated from the
controller. That is, when the operation starting signal PCD_ON of
the safety driving apparatus is increased to an on-level, the panel
detector 41 of the safety driving apparatus operates. Then, the
panel detector 41 detects an error or not of the voltage level due
to external damage to the display panel by applying a predetermined
reference voltage through a detection line of the display panel and
detecting an output voltage in response thereto.
[0097] For a period of the time t3 to a time t4, the detection
result signal PCD_out determining the damage to the display panel
is output at a normal level. In the exemplary embodiment of FIG. 4,
the detection result signal PCD_out of the normal panel has the low
level, but it may depend on a configuration of the logic gates of
the combination logic 16 of the panel detector 41 as described
above.
[0098] In the exemplary embodiment of FIG. 4, at the time t4, the
low-level detection result signal PCD_out of the normal panel is
increased to the high-level. This represents a state where the
output voltage is output to an over-voltage state as compared with
the reference voltage or output to an opened voltage due to the
damage to the display panel. Accordingly, the detection result
signal PCD_out of the abnormal panel is transferred to the panel
protector 45 through the controller to interrupt the driving of the
display device.
[0099] In detail, the panel protector 45 transfers the detection
result signal PCD_out to an internal host of the display device to
soft-reset the driving IC or shut down the DC-DC converter. Then,
at the time t4, the enable signal EL_ON of the DC-DC converter
supplying a power source to the display device is changed to the
low level.
[0100] As an exemplary embodiment, a circuit may be configured so
that the driving IC may automatically perform the soft-reset, or
may instruct so as to perform the soft-reset operation of the
driving IC after receiving the detection result signal PCD_out from
the host. As described above, in the example embodiments, methods
in which the panel protector 45 interrupts the driving of the
display device are various according to the detection result signal
PCD_out representing the damage to the panel, and the control
signal is generated according to the method to be transferred to
the driver.
[0101] Therefore, according to the exemplary embodiments, it is
possible to provide safety protection measures against abnormal
implementation of a display screen due to the occurrence of cracks,
scratches, or breakage on a module or a panel caused by external
damage and damage on a product such as overheating or fire.
Further, it is possible to prevent possibility of an injury to an
end user in advance by early detection of an error of the display
panel and embedding a driving system of safely protecting the
display panel. In addition, the safety driving system in the
display device can be applied from small-sized mobile apparatuses
to medium and large-sized modules.
[0102] That is, according to example embodiments, even if the
display panel is only partially damaged, protection from potential
overheating and fire may be provided. For example, a rapid
resolution may be provided for a situation when the power source
applied to the display panel is shorted or opened, thereby
preventing abnormal display of a screen or preventing abnormal
operation of a driving power source.
[0103] In contrast, when a conventional display panel is damaged
and the user is unable to detect the damage at an early stages, by
the time the user is able to detect the damage with a naked eye,
the breakdown of the display device may be already at a progressive
stage. For example, image quality may be deformed and fire due
overheating may occur and burn the user.
[0104] The drawings referred to in the above and disclosed
description of the example embodiments only illustrate the example
embodiments, and are intended to describe the example embodiments,
not to restrict the meanings or the scope of the example
embodiments claimed in the claims. Therefore, those skilled in the
art can easily select and substitute the drawings and disclosed
description. Those skilled in the art can omit some of the
constituent elements described in the present specification without
deterioration in performance thereof or can add constituent
elements to improve performance thereof. Furthermore, those skilled
in the art can modify the sequence of the steps of the method
described in the present specification depending on the process
environment or equipment. Therefore, the scope of the example
embodiments must be determined by the scope of the claims and the
equivalent, not by the described embodiments.
DESCRIPTION OF SYMBOLS
TABLE-US-00001 [0105] 1: Display panel 2: Driving IC 21: voltage
input terminal 22: voltage output terminal 3-1, 3-2: Detection
lines 4: Safety driving apparatus 41: Panel detector 43: Controller
45: Panel protector
* * * * *